CRT (Cathode Ray Tube) displays have been gradually replaced by LCD (Liquid Crystal Display) devices and OLED (Organic Light Emitting Diode) display devices in the technical field of display. The OLED display device is expected to become the core display in the next generation of flat panel display technology by virtue of its advantages of being active in light emitting, quick in response, wide in viewing angle, high in brightness and color saturation, low in cost, light, thin and flexible, etc. Based on light emitting directions, OLEDs are classified into bottom-emission OLEDs (namely, emitting light downwards relative to the substrates), top-emission OLEDs (namely, emitting light upwards relative to the substrates), and other OLEDs. As the top-emission OLED has the advantages of a high aperture ratio and color purity, easiness in achievement of a high resolution (Pixels per inch, (PPI)), and the like, it has become a mainstream organic electroluminescent device structure at present.
The OLED is a current driving component mainly composed of a second electrode, a light emitting function layer, and a first electrode which are sequentially away from a substrate. As a light emitting direction of the top-emission OLED is located at one side of the first electrode, the first electrode is required to have higher light transmittance and conductivity. The first electrode is generally made of a single metal and/or an alloy material with a low work function, so a light transmittance rate of the first electrode is smaller. Thus, in order to reduce the influence of the first electrode on the light emitting rate, the first electrode is required to be very thin. However, the resistance of the thinner first electrode is larger, which will cause an obvious voltage drop (IR Drop). As a result, emitted light is non-uniform due to non-uniform voltage distribution on the first electrode, and accordingly, power consumption is increased.
In order to solve the problem, a solution in which an auxiliary electrode is arranged on an array substrate had been provided. According to the solution, the auxiliary electrode with a lower resistance is connected to the first electrode to reduce the voltage drop and increase the uniformity of emitted light.